Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 21: Polymer Physics II
CPP 21.11: Vortrag
Mittwoch, 25. März 2009, 12:15–12:30, ZEU 114
Microrheology with Fluorescence Correlation Spectroscopy — •Silke Rathgeber1,2, Hans-Josef Beauvisage1, Hubert Chevreau1,3, Norbert Willenbacher4, and Claude Oelschlaeger4 — 1Max Planck-Institute for Polymer Research, 55128 Mainz, Germany. — 2Johannes Gutenberg-University Mainz, 55099 Mainz, Germany. — 3Ecole Polytechnique Universitaire de Lille, 59655 Villeuneuve D` Ascq Cedex, France. — 4Technical University Karlsruhe, 76131 Karlsruhe, Germany.
We show that fluorescence correlation spectroscopy (FCS) can be applied to passive microrheological (MR) experiments. We performed measurements on a high molecular weight poly(ethylene oxide)-water solution in order to allow direct comparison of the results to the measurements of Weitz and Mason using diffusing wave spectroscopy (DWS) and quasielastic light scattering (QELS). We derived the bulk rheological shear moduli covering more than five decades in frequency (ω≤ 10−1 rad/s to ω≥ 104 rad/s). The MR results are compared to those obtained with bulk rheological methods on the same samples using a rotational rheometer as well as a piezo driven squeeze flow apparatus. Good agreement between MR results probing the local rheological response and those obtained from the bulk methods are found. MR with FCS covers a similar ω range as QELS and DWS together with some limitations to higher ω due to the lower spatial resolution of FCS compared to DWS. However, the small sample sizes (10 µ L) and small tracer concentrations (nM) involved in FCS make this method a powerful tool in particular for biological and medical applications.